Thermodynamic studies like density (ï² ), specific gravity, ultrasonic speed ( u ) and excessmolar volume ( E m V ) and molar excess enthalpy of binary liquid mixtures of toluene + 1,2-dichloroethane have been carried out over the different range of composition at 303.15 K. Thermodynamic parameters like isentropic compressibility s K , intermolecular free length, Lf, Relative association, Ra, have been computed fromexperimental findings. The excess thermodynamic functions have been fitted to the Redlich- Kister polynomial equation. The experimental ultrasonic speeds have been analyzed in terms of Jacobson Free Length Theory (FLT), SchaaffÂs Collision Factor Theory (CFT), NomotoÂs relation, and Van DaelÂs ideal mixture relation. Intermolecular Free Length, f L , and available volume, a V , have been calculated from FLT, CFT and thermoacoustic approach. It is observed that density and specific gravity increases and ultrasonic speed, isentropic compressibility and intermolecular free length decreases with the mole fraction of 1,2-dichloroethane. It is found that intermolecular interactions present between binary liquid mixtures are stronger than pure solvent-solvent interactions. Observed negative values of excess molar volume and positive value of molar excess enthalpy confirm the presence of specific chemical attractive force of interactions between the two binary liquid mixtures.